1. Field of the Invention
The present invention relates to a fold section feeding out apparatus located below a delivery fan in a folding unit for a rotary press. More particularly, the invention relates to a fold section feeding out apparatus of a folding unit for a rotary press, which can prevent a rear end portion of a fold section ejected from the delivery fan from being turned over.
2. Description of the Related Art
A fold section feeding out apparatus of a folding unit for a rotary press as set forth above has been known as disclosed in Japanese Patent No. 2548079, for "Fold Section Feeding Out Apparatus of Folding Unit", for example. Also, mechanisms ejecting an air in the vicinity of a delivery fan have been known as disclosed in Japanese Unexamined Utility Model Publication No. Hei 4-96457 for "Ejection Device of Folding Machine for Rotary Press", Japanese Unexamined Patent Publication No. Hei 4-80036 for "Method and Apparatus for Preventing Electrostatic Sticking of Printing Paper", for example.
The fold section feeding out apparatus disclosed in the above-identified Japanese Patent No. 2548079 is a feeding out apparatus constructed with two conveyers cooperatively actuated for adjusting a distance between an outer periphery of the delivery fan and an upper surface of the conveyer, namely for adjusting a dropping distance so that the conveyer may not be excessively distant from the delivery fan, for avoiding jumping of the fold section in reaction to it dropping upon transfer to the upper surface of the conveyer when the fold section is transferred from the delivery fan.
On the other hand, the ejection device disclosed in Japanese Unexamined Utility Model Publication No. Hei 4-96457 takes a measure for drawback to be caused by static charge of the fold section in the delivery fan. A guide having an air blowing opening blowing an air between vanes at a position for receiving a fold section folded and fed from a folding machine by the delivery fan, is provided. Also, a stopper having an air blowing opening blowing an air onto a back surface of the delivery fan is provided. By blowing the air or ionized air from the blowing opening, the fold section is moved to a desired position against a force adhering the fold section onto the surface of the vane by static charge, or the fold section is prevented from adhering onto the surface of the vane by static charge and moved to the desired position.
Also, the apparatus disclosed in Japanese Unexamined Patent Publication No. Hei 4-80036 is constructed to prevent mutual electrostatic sticking of the fold section, by ejecting and spraying a sliding agent, such as that consisted of fine powder on the mutually mating surfaces of the fold sections, through a nozzle arranged in opposition to the delivery fan.
On the other hand, in the rotary press always driven at a high speed, for example, the rotary press having a normal printing speed of a hundred-thirty thousands copies or more per hour, when printing is performed at the normal printing speed, as shown in FIGS. 4 and 5 (these figures are similar to FIG. 1 while a delivery fan and a conveyer are omitted from illustration), when the fold section 74b or 74t drops onto the conveyer from the delivery fan, all of the rear end portions of the fold sections 74b or 74t are cut, and so-called leaf form rear end portions 36 are laid on the conveyer an cause significant rebound due to reaction of the impact. Then, subsequent bag form fold section 73b or 73t may be stacked over the rebounded rear end portion to form turned over portion 33b or 33t.
Namely, as shown in FIG. 4, in case of the fold section where one of the side ends of the fold section 74b forms the bag form side end portion 34b and the other side end is cut to form the leaf form side end portion 35 (hereinafter referred to as "broad sheet"), the rear end portion 36 of the fold section drops from the delivery fan onto the conveyer with impact. Therefore, the leaf form side end portion 35 having a low stiffness may be rebounded to cause triangular turning back. Then, the subsequent broad sheet 73b stacks over the rebounded portion to form the rebounded triangular turned back portion 33b.
On the other hand, as shown in FIG. 5, for example, in case of the fold section 74t where the both side portions are cut to form the leaf form side end portion 34t and 35 and to form the bag form only at the tip end (hereinafter referred to as "Tabloid sheet"), the rear end portion 36 of the Tabloid sheet 74t which has a low stiffness over the entire portion, drops from the delivery fan onto the conveyer with impact to cause rebounding at the entire rear end portion 36. Then, the subsequent Tabloid sheet 73t is stacked over the rebounded portion to form a parallel strip form turned over portion 33t.
The higher the normal printing speed of the rotary press, the higher the possibility of formation of the triangular turned over portion 33b or the parallel strip form turned over portion 33t becomes. And also the greater the number of pages of the fold section, the higher the possibility of formation of the triangular turned over portion 33b or the parallel strip from turned over portion 33t becomes. Occurrence of such turned over portions inherently interfere with operation of the apparatus in the downstream side process. In conjunction therewith, presence of such turned over portions should degrade commercial value and can be a hazard for a high speed printing of the rotary press.
In contrast with this, the fold section feeding out apparatus as disclosed in the above-identified Japanese Patent No. 2548079, permits adjustment of appropriate drop speed so as not to cause rebounding of the fold section by reaction upon dropping of the fold section from the delivery fan onto the conveyer by moving the transporting apparatus constituted of cooperatively operating two conveyers to prevent rebounding of the rear end portion of the fold section.
However, the drop distance has to be adjusted every time the number of pages of the fold section is varied. Furthermore, the distance has to be adjusted frequently depending upon the printing speed during printing. Constantly maintaining the fold section having no turned over portion requires skill of the operator in operation, and further requires substantial work load in operation. In addition, the feeding out apparatus as disclosed is constructed with a large number of parts to be expensive and troublesome in maintenance.
On the other hand, the ejection device as disclosed in the above-identified Japanese Unexamined Utility Model Publication No. Hei 4-96457, is provided with the air blowing opening in the guide guiding the fold section to the delivery fan, and is also provided with the air blowing opening in the stopper which pushes the fold section from the delivery fan onto the conveyer, for blowing the air or ionized air to move the fold section to the desired position against adhering force due to static charge or to extinguish the adhering force due to static charge by removing the static charge and to move the fold section to the desired position. However, the disclosed ejection device is not effective for preventing turning over the fold section.
Furthermore, in the above-identified Japanese Unexamined Patent Publication No. Hei 4-80036, there is provided a nozzle ejecting fine powder in opposition to the delivery fan for ejecting and spraying the fine powder on the mutually stacked surface of the fold sections in order to prevent electrostatic sticking or adhesion of the fold sections with each other. However, it is not possible to prevent the fold section from causing turning over.
In addition, a large fraction of the ejected and sprayed powder fly off the environment and is accumulated. Therefore, frequent cleaning becomes necessary. Furthermore, the flying powder should degrade work environment. Also, the powder may penetrate into the mechanical parts and cause shortening of the life of the machine. Furthermore, the powder deposited on the fold section contaminates the apparatus in the downstream process and inherently gives the printing paper surface a harsh feel.